Principles of Electromechanical Energy Conversion - Flow of energy in electromechanical devices, Energy in magnetic systems (Defining energy and Co-energy),Singly excited systems; Determination of mechanical force, Mechanical energy, Torque equation , Doubly excited systems; Energy stored in magnetic field, Electromagnetic torque , Generated e.m.f. in machines; Torque in machines with cylindrical air gap . D.C. Machines : Construction of d.c. machines, Armature winding, E.M.F. and torque equation, Armature reaction, Commutation, Interpoles and compensating windings, Performance characteristics of d.c. generators. D.C. Machines (Contd.) : Performance characteristics of d.c. motors, Starting of d.c. motors ; 3 point and 4 point starters , Speed control of d.c. motors: Field control, Armature control and voltage control (Ward Lenonard method); Efficiency and testing of d.c. machines (Hopkinsons and Swinburns test). Single Phase Transformer : Phasor diagram, Efficiency and voltage regulation, All day efficiency. Testing of Transformers : O.C. and S.C. tests, Sumpners test, Polarity test. Auto Transformer : Single phase and three phase auto transformers, Volt-amp, Relation, Efficiency, Merits and demerits and applications. Three Phase Transformers : Construction, Three phase transformer phasor groups and their connections, Open delta connection, Three phase to 2 phase, 6 phase or 12 phase connections, and their applications, Parallel operation and load sharing of single phase and three phase transformers, Excitation phenomenon and harmonics in transformers, Three winding transformers.